Argentina's president is accusing Britain of militarising the South Atlantic and says she will complain to the United Nations.
Tension is rising ahead of the 30th anniversary of the war between Britain and Argentina over the British-ruled Falkland Islands.
In a speech, Argentine president Cristina Fernandez criticised the deployment of British destroyer HMS Dauntless in the area.
She also criticised Prince William's posting as a military search-and-rescue pilot in the islands.
Ms Fernandez said the foreign ministry would present a formal complaint to the UN Security Council and general assembly.